Tape-stripping of the skin is a useful method for removing the stratum corneum and obtaining more information about the function of this skin layer as the main barrier for skin penetration. The amount of stratum corneum removed is of relevance in establishing the concentration pro¢ le of chemicals within the stratum corneum after topical application. Weighing is the preferred method for measuring the amount stripped, but because it is often subject to artifacts, alternative methods are sought. We present a simple, colorimetric method for determining the amount stratum corneum removed by sequential adhesive-tape-stripping of human skin in vivo. The method is based on quanti¢ cation of the sodium hydroxide soluble protein fraction using a commercially available protein assay similar to the Lowry assay. The method is shown to be an accurate and reproducible alternative to weighing, also demonstrating uniform removal of stratum corneum layers following the very initial strips.